I saw A New Hope when it first came out in the theatre. I was a few months shy of my 3rd birthday. No joke. It was the first movie I saw in a movie theatre.
Now I have a 4-year-old and I can't remember when he first saw bits and pieces of the Star Wars franchise. I can't say he's seen an entire movie, as he can't sit still for one, but we've had them on while he's around and he occasionally hangs out long enough to get the gist. He certainly knows Darth Vader, Han Solo, Yoda, stormtroopers, etc...
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Questionable parent that I am, he's also seen a good portion of the Harry Potter movies as well...
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